//
// MD5Engine.h
//
// Library: Foundation
// Package: Crypt
// Module:  MD5Engine
//
// Definition of class MD5Engine.
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier:	BSL-1.0
//
//
// MD5 (RFC 1321) algorithm:
// Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
// rights reserved.
//
// License to copy and use this software is granted provided that it
// is identified as the "RSA Data Security, Inc. MD5 Message-Digest
// Algorithm" in all material mentioning or referencing this software
// or this function.
//
// License is also granted to make and use derivative works provided
// that such works are identified as "derived from the RSA Data
// Security, Inc. MD5 Message-Digest Algorithm" in all material
// mentioning or referencing the derived work.
//
// RSA Data Security, Inc. makes no representations concerning either
// the merchantability of this software or the suitability of this
// software for any particular purpose. It is provided "as is"
// without express or implied warranty of any kind.
//
// These notices must be retained in any copies of any part of this
// documentation and/or software.
//


#ifndef Foundation_MD5Engine_INCLUDED
#define Foundation_MD5Engine_INCLUDED


#include "Poco/DigestEngine.h"
#include "Poco/Foundation.h"


namespace Poco
{


class Foundation_API MD5Engine : public DigestEngine
/// This class implements the MD5 message digest algorithm,
/// described in RFC 1321.
{
public:
    enum
    {
        BLOCK_SIZE = 64,
        DIGEST_SIZE = 16
    };

    MD5Engine();
    ~MD5Engine();

    std::size_t digestLength() const;
    void reset();
    const DigestEngine::Digest & digest();

protected:
    void updateImpl(const void * data, std::size_t length);

private:
    static void transform(UInt32 state[4], const unsigned char block[64]);
    static void encode(unsigned char * output, const UInt32 * input, std::size_t len);
    static void decode(UInt32 * output, const unsigned char * input, std::size_t len);

    struct Context
    {
        UInt32 state[4]; // state (ABCD)
        UInt32 count[2]; // number of bits, modulo 2^64 (lsb first)
        unsigned char buffer[64]; // input buffer
    };

    Context _context;
    DigestEngine::Digest _digest;

    MD5Engine(const MD5Engine &);
    MD5Engine & operator=(const MD5Engine &);
};


} // namespace Poco


#endif // Foundation_MD5Engine_INCLUDED
